Six Degrees of Kevin Bacon

The trivia game Six Degrees of Kevin Bacon is based on a variation of the concept of the small world phenomenon which states that any actor can be linked, through their film roles, to Kevin Bacon. The game requires a group of players to try to connect any film actor in history to Kevin Bacon as quickly as possible and in as few links as possible. The game was devised by three college students, Mike Ginelli, Craig Fass, and Brian Turtle in 1994. (Ginelli and Turtle later appeared as two members of the team "Peanut Butter and Ginelli" on 2006's VH1 World Series of Pop Culture.) Its name is a pun on the stage play Six Degrees of Separation, based on the title rhyming with Bacon's name.

The concept

The concept is simple, but finding the smallest number of links can be difficult. The way you link an actor with Bacon is like so:

• Pick any film actor in history.
• Link the actor you've chosen to Bacon via the movies they've shared with other actors until you end up with Kevin Bacon himself.

Here is an example, using Elvis Presley:

1. Elvis Presley was in Change of Habit (1969) with Edward Asner
2. Edward Asner was in JFK (1991) with Kevin Bacon

Therefore Elvis Presley has a Bacon number of 2.

The game has expanded to become more about linking two film actors than just one actor to Kevin Bacon. The name is still retained, however, because it has been shown that Bacon is a common link member in a chain.

Better Centers

Notably, Bacon is not the most linkable actor. According to the Oracle of Bacon site, that honour goes to Rod Steiger. The average Steiger number in the acting community is 2.679.[1] By contrast, the average Bacon number is 2.946.[2]

Undefined Bacon numbers

Very few actors have an undefined (or infinite) Bacon number, meaning that they cannot be linked to Bacon in any number of connections at all. For instance, Fred Ott appears in the 1894 Edison Kinetoscopic Record of a Sneeze; he was the only actor in that film and also acted solo in Fred Ott Holding a Bird — the only films in which he appeared. (Ott was not a professional actor; he was a lab technician in the laboratory where Edison's Kinetoscope was developed.) Most actors, however, can be linked to Bacon. As of December 2005, there were 9,692 actors in the IMDb who could not be linked to Kevin Bacon out of the total of 418,468 (approx. 2.3%).[3]

Variations of the Six Degrees of Kevin Bacon game

The Six Degrees of Kevin Bacon game sometimes fails to model the real world as it allows both forward and backward linkings. Very frequently, only one kind of linking is allowed between two nodes.

Forward linking

For example, the spreading of any virus is forward in time. If John Doe catches a virus on Monday, Jane Doe, who only had contact with him two days before that could not get the virus because of her previous contact with John. However if she came into contact with him after she may contract the virus.

For John Doe to transmit the virus to Jane Doe, it may require following steps:

John Doe -> Jack (3 days later) -> Tom (3 days later) -> Jane Doe (3 days later)

Backward linking

However, if John Doe is running a peer-to-peer file exchange program like Kazaa, he needs links backward in time. He does not care who will get a piece of the file in the future. He wants to know who already had that piece of file at hand.

For John Doe to receive a piece of file, that particular information could be travelling in this manner:

John Doe <- Jack (2 minutes ago) <- Tom (5 hours ago) <- Mary (4 days ago) <- Seed (1 week ago)

So there are two ways to link, for example, Jennifer Lopez with Kevin Bacon:

• Forward linking from Lopez to Bacon

1. Jennifer Lopez was in U Turn (1997) with Sean Penn
2. Sean Penn was in Mystic River (2003) with Kevin Bacon

• 1997 -> 2003

• Backward linking from Lopez to Bacon

1. Jennifer Lopez was in Gigli (2003) with David Pressman
2. David Pressman was in Pyrates (1991) with Kevin Bacon

• 2003 <- 1991

Bi-directional linking

Anyone with a Bacon number of 2 could not have a link of both forward and backward steps. However, with many people who died long ago, pure backward linking is simply impossible, if the use of stock footage is ruled out. For example, John F. Kennedy, who died in 1963 could not be performing with anyone after 1975, Bacon's first TV appearance, or 1978, his first film appearance.

• Shortest Path from JFK to Bacon (A)

1. John F. Kennedy was in Zapruder Film of Kennedy Assassination (1963) with Jean Hill
2. Jean Hill was in Beyond 'JFK': The Question of Conspiracy (1992) with Gary Oldman
3. Gary Oldman was in Murder in the First (1995) with Kevin Bacon

• 1963 -> 1992 -> 1995 (forward steps)

• Shortest Path from JFK to Bacon (B)

1. John F. Kennedy was in Zapruder Film of Kennedy Assassination (1963) with Jean Hill
2. Jean Hill was in Beyond 'JFK': The Question of Conspiracy (1992) with Edward Asner
3. Edward Asner was in JFK (1991) with Kevin Bacon

• 1963 -> 1992 <- 1991 (bi-directional steps, backward steps impossible)

Distant links

Elsa Masriera has a Bacon number of 7, if bi-directional links are allowed.

• Shortest Path from Elsa Masriera to Kevin Bacon (A)

1. Elsa Masriera was in Madre sin saberlo (1927) with Mercedes Olivares
2. Mercedes Olivares was in Bajo dos banderas (1926) with Edmundo Fuenzalida
3. Edmundo Fuenzalida was in Los Cascabeles de Arlequin (1926) with Placido Martin
4. Placido Martin was in Suena mi amor (1946) with Chela Bon
5. Chela Bon was in Curse of the Stone Hand (1964) with John Carradine
6. John Carradine was in The Sentinel (1977) with Eli Wallach
7. Eli Wallach was in Mystic River (2003) with Kevin Bacon

• 1927 <- 1926 -> 1926 -> 1946 -> 1964 -> 1977 -> 2003 (bi-directional)

• Shortest Path from Elsa Masriera to Kevin Bacon (B)

1. Elsa Masriera was in Madre sin saberlo (1927) with Mercedes Olivares
2. Mercedes Olivares was in Bajo dos banderas (1926) with Edmundo Fuenzalida
3. Edmundo Fuenzalida was in Los Cascabeles de Arlequin (1926) with Placido Martin
4. Placido Martin was in El Ultimo galope (1951) with Yoya Martinez
5. Yoya Martinez was in "Marron Glace, el regreso" (1996) with Walter Kliche
6. Walter Kliche was in The Lawless Land (1988) with Xander Berkeley
7. Xander Berkeley was in Apollo 13 (1995) with Kevin Bacon

• 1927 <- 1926 -> 1926 -> 1951 -> 1996 <- 1988 -> 1995 (bi-directional)

Photography book

Inspired by the game, the British photographer Andy Gotts tried to reach Bacon through photographic links instead of film links.

He wrote to 300 actors asking to take their pictures, and received permission from one, Joss Ackland. Ackland then suggested that Gotts photograph Greta Scacchi, with whom he had appeared in the film White Mischief. Gotts proceeded from there, asking each actor to refer him to one or more friends or colleagues. Eventually, Christian Slater referred him to Bacon. Gotts's photograph of Bacon completed the project, eight years after it began. Gotts published the photos in a book, Degrees (ISBN 0954684362), with text by Alan Bates, Pierce Brosnan, and Bacon. [4]

See also

• Bacon numbers for a lot more information on Bacon numbers and how to calculate them.
• Erdős-Bacon numbers for a mathematician's further extension of this game.

External links

• The Oracle of Bacon, with an automated Bacon calculator provided by the University of Virginia
• Band To Band, links any band to any other band using albums, similar to the Kevin Bacon game
• Cinema FreeNet Movie Connector finds links between movie stars, and can also use directors and producers.
• The Amazing Baconizer, finds the shortest path between any two books, movies, or CDs offered on Amazon.com, by building paths out of the "people who bought this item also bought these ten other items" links.
• Omnipelagos, finds the shortest (or most obscure) paths between any two terms in the Wikipedia.
• Six degrees tool - Finds the shortest path between any two Wikipedia articles in the main namespace using wiki links. The source is also available.
• Social Network - Makes it possible to meet people and also show their relation to you